A GP has been suspended for three months after prescribing oral isotretinoin to a young woman who became pregnant while on the acne treatment, resulting in fetal cranial and cardiac malformations.

He claimed he had felt pressured to prescribe the medication after her family rejected a referral for a dermatologist because they could not afford it.

He also said he had been told by a local pharmacist that GPs were authorised to prescribe the drug, which is currently restricted under the PBS to physicians and dermatologists.

In a series of hearings into the case, the NSW Civil and Administrative Tribunal was told he did not request pregnancy testing before writing the script for the 17-year-old.